1. Field of the Invention
The present field of the invention is related to a Front Opening Unified Pod (FOUP), and more particularly, to the lock-fastening structure of robotic flange of FOUP and its assembly method.
2. Description of the Prior Art
The semiconductor wafers are transferred to different work stations to apply the various processes in the required equipments. A sealed container is provided for automatic transfer to prevent the pollution from occurring during transferring process. FIG. 1 is a view of wafer container of the prior art. The wafer container is a Front Opening Unified Pod (FOUP) which includes a container body 10 and a door 20. The container body 10 is disposed with a plurality of slots 11 for horizontally placing a plurality of wafers, and an opening 12 is located on a sidewall of the container body 10 for importing and exporting the wafers. The door 20 further includes an outer surface 21 and an inner surface 22, wherein the door 20 is joined with the opening 12 of the container body 10 via the inner surface 22 to protect the plurality of wafers within the container body 10. Furthermore, at least one latch hole 23 is disposed on the outer surface 21 of the door 20 for opening or closing the wafer container. According to the aforementioned, due to that the wafer is horizontally placed in the container body 10, thus, a wafer restraint component is needed in the FOUP to prevent the wafer from displacement or from movement toward the opening of container body 10 to occur during the wafer transportation due to vibration.
To ensure a smooth process of transferring the FOUP between different stations, a robotic flange (not shown in Figure) is disposed on the top of the container body of FOUP for being gripped by an automation machine. In the FOUP disclosed in U.S. Pat. No. 6,010,008 and U.S. Pat. No. 7,357,257, screws and linear grooves are utilized for fixing the robotic flange to the top of the container body. However, when linear grooves are disposed on the robotic flange and linear snap-hooks are disposed on the top of the container body, abrasion or particles easily occur due to friction. Moreover, utilization of linear grooves only may lead to the fixing of the front end of robotic flange to the back end of the top and the result is that the robotic flange is reversely fixed to the FOUP and cannot be gripped by the automation machine.